JPH10231A - Lubricant for shaping top of catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a lubricant solution reduced in raw materials and cost required for shaping the top of catheter without using a chlorofluorocarbon as a solvent nor being flammable. SOLUTION: A two component lubricant for shaping the top of catheter contains water as a solvent. The lubricant comprises a nonionic silicone-based surfactant and a fluid having an excellent lubricity (releasability). The use of other surfactants or lubricants is not necessary. This lubricant solution for immersing a catheter may contain a low ratio stabilizer solution for clarifying the solution and an antibacterial agent for preventing the growth of bacteria in the solution. Further, vitamine E or its derivatives may be contained in the solution for preventing decomposition of the solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION The present invention generally relates to tipping lubricant systems used during the manufacture of intravenous (IV) catheters.
About.

[0002] IV catheters are designed to inject a standard intravenous solution containing antibiotics and other drugs into a patient. These catheters use standard blood-
It is also used to draw blood from patients for gas analysis and other blood testing tasks. A guide needle is used to insert the IV catheter into the patient. This needle is generally made of stainless steel and is hollow. The distal tip is ground to a sharpened tip to facilitate insertion into a patient. The catheter is also hollow and is first positioned coaxially around the introducer needle in a "needle-over" manner. The catheter is made of a suitable plastic material, such as Teflon,
Injection molded from polyvinyl chloride, polyethylene, polyurethane or polyether urethane. The inner diameter of the catheter tip is slightly smaller than the outer diameter of the needle tip, so the catheter tip is an interference fit with the needle tip. This interference fit is necessary so that when the catheter and introducer assembly is removed from the package, the catheter remains snug with the needle and cannot be easily removed. This interference fit also facilitates insertion of the needle and catheter assembly into the patient's vein. This reduces the chances that the tip of the catheter will be folded and will cover or peel off the tip of the needle.

[0003] The shape of the catheter tip must be minimally traumatic to the patient during insertion of the catheter into the patient and while the catheter is in place within the patient. Such a preferred tip configuration with these characteristics is one having a tapered outer wall and a beveled tip, and is disclosed in U.S. Pat. No. 4,588,398. A method of forming the catheter tip is disclosed in U.S. Pat. No. 4,661,300. In this method, a catheter is placed on a mandrel. A die having a mold surface tapered according to the desired tip of the catheter is arranged coaxially with the mandrel. Generally, the catheter tip is heated by high-frequency energy so as to be fluid. The mandrel and die are mated so that the distal end of the mandrel engages the tapered portion of the die. This action forms a smooth and uniformly tapered tip on the catheter.

[0004] After the catheter has been tipped, it must not have defects such as incomplete molding, substantial burrs, or jagged ends. The tip must look smooth and roll-over
There must be no. In addition, the length of the catheter must still be within target specifications after tip molding. If the thermoplastic material adheres to the die or mandrel during tip forming, the length will vary significantly with stretching and the tip will have defects. To determine if the tip is defective and the catheter length is within specifications,
Visual or microscopic examination can be employed.

[0005] Lubricant is commonly used to facilitate removal of the tip-formed catheter from the mandrel and die.
t) (release agent) is used. If no lubricant is used, the tip-formed catheter will stick to the mandrel or die and may deform when removed from the mandrel or die. Standard tipping lubricants include polydimethyl siroquine, such as Dow Corning DC 360, or curable silicone, such as Dow Corning 441.
59 MDX, which have amine end groups,
Moisture curable. Non-curable amine-terminated polydimethylsiloxanes have also been used for this purpose. These lubricants are described, for example, in US Pat. No. 3,574,673;
4,904,433; and 5,185,006.

[0006] Only a small amount of lubricant is required to provide lubricity (release) between the catheter and the mandrel and die. Therefore, to control the application of lubricant, the catheter is immersed in a solution containing lubricant. The use of a solution facilitates the application of the lubricant to the inner surface as well as the outer surface of the catheter.

[0007] Silicone oil used as a general lubricant is hydrophobic. Therefore, these compounds must be dissolved in an organic solvent in order to prepare a solution that can immerse the catheter tip for lubricity prior to the start of tip shaping. The main solvent used is freon. This is because it is flame retardant and evaporates quickly. Unfortunately, chlorofluorocarbons (CF
Due to recent concerns that C) will destroy the ozone layer that protects the earth, the production and use of CFCs will be discontinued in the near future. Therefore, other solvents must be used. Other organic solvents, such as alcohols and hydrocarbons, are highly flammable and are undesirable.

Attempts have been made to obtain lubricant systems using water as a solvent. Such systems are generally ternary systems using lubricants, surfactants and water. U.S. Pat. No. 5,266,359 discloses such a three-component system using water as a solvent. Such a three-component lubricant system using water as a solvent is "green" and not flammable, but leaves room for improvement. Since a three-component lubricant system obviously requires three separate components, the materials and manufacturing operations required to apply the system to the medical device to be lubricated involve a certain amount of expense.

[0009] SUMMARY Accordingly, an object of the present invention the invention is to provide the necessary free tip molding lubricant using CFC as a solvent.

Another object of the present invention is to provide an "environmentally friendly"
It is to provide a lubricant solution for tip molding.

Yet another object of the present invention is to provide a tip-forming lubricant solution that is not flammable.

It is yet another object of the present invention to provide a tipping lubricant solution that requires less material and cost than other tipping lubricant solutions.

[0013] The lubricant solution for tip molding of the present invention is a two-component system and contains water as a solvent. This lubricant is a silicone surfactant, which is a good lubricating fluid. No other substance is required to provide lubrication, the silicone surfactant alone provides lubrication and is itself water-soluble. Therefore, the use of a solution of silicone surfactant and water makes it possible to easily apply the silicone surfactant to medical devices or other devices, and when the water evaporates, the surface to which the silicone surfactant has been applied surely has lubricity. Become. Preferably, a nonionic silicone surfactant is used. This is because they seem to be less toxic. The lubricant solution in which the catheter is immersed can also contain low proportions of solution stabilizers and antimicrobial agents to clarify the solution and inhibit microbial growth in the aqueous solution. Further, the lubricant solution may contain vitamin E or a derivative thereof.

The above and other objects and advantages of the present invention will become apparent in view of the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION Although the invention has been described as applied to IV catheters and introducer needles, it should be understood that the invention can be used with other medical devices where a lubricious surface on the device is desired.

The lubricant for tip molding of the present invention is a two-component system of a silicone surfactant and water. Preferably, the silicone surfactant is a polyalkylene oxide-dimethylsiloxane-copolymer, such as a Silwet silicone surfactant sold by OSI Specialties. These surfactants are polyalkylene oxide modified polydimethylsiloxane-block copolymers. These are similar to standard silicone fluids, except that the polydimethylsiloxane backbone has a non-ionic surfactant, such as a poly (oxyethylene) poly (oxypropylene) block copolymer known as a pluronic polyol, with a polyalkylene oxide side chain. With chains. These side chains have hydroxy or lower alkoxy end groups. The molecular structure of Silwet L7001 silicone surfactant is shown below:

Embedded image This silicone surfactant has a molecular weight of 20,000 and a viscosity of 1700 centistokes and is soluble in water. Preferably, about 2 to about 6% silicone surfactant is used in the lubricant solution. A combination of undiluted base silicone surfactant and undiluted amino-modified-base silicone surfactant can be used as a lubricant. When a combination of an amino-modified-base silicone surfactant and an undiluted base silicone surfactant is used as a lubricant, preferably about 2 to about 6
Use the above combination of%. Alternatively, an amino-modified-base silicone surfactant can be used alone as a lubricant. In this case, about 2 to about 6% of the amino-modified-based silicone surfactant is used in the solution.

Vitamin E may be added to the above solution.
Vitamin E is chemically known as α-tocopherol and is an antioxidant. Vitamin E is an antioxidant and thus prevents degradation of the lubricant solution due to oxidation, thus minimizing the effects of aging. Further, vitamin E and its derivative vitamin E acetate enhance the lubricity of the lubricant of the present invention. Preferably, 0.1 to 1% of vitamin E and its derivative vitamin E acetate are used. The molecular structure of vitamin E is shown below:

Embedded image

Cosmocil, a polyhexamethylene biguanide hydrochloride, is an excellent solution stabilizer and an antimicrobial that inhibits the growth of microorganisms in the aqueous solution or on the coated product, so that Can be added. Preferably about 1 to about 5% cosmosil is used. Other antimicrobial agents that can be used include: iodine carriers; phenols; phenolic compounds such as p-chloro-m-xylenol; and other biguanides such as chlorhexidine gluconate. Preferably, Cosmosil is used. This is because it is less toxic than other antibiotics. Its molecular structure is shown below:

Embedded image

The catheter blank to be tipped may be dipped in pure, ie, 100% lubricant. Preferably, the catheter blank is immersed in the lubricant solution of the present invention. Only the tip portion of the catheter need be immersed in the above solution. The duration of the immersion step is not critical. The lubricant solution can also be applied by brushing or spraying. Solvents can be removed by evaporation or warming at ambient conditions.

After applying the lubricant solution, the catheter is placed on a mandrel and heated. The tip of the catheter is formed by fitting the die and the mandrel. This tip-shaped catheter can then be easily and quickly removed from the die and mandrel.

Example 1 The following table shows the effect of using various amounts of silicone surfactant and amino-modified silicone surfactant as a lubricant.

[0022]

Table 1 1 2 3 4 Silicone surfactant (%) 3.00 3.00 4.50 3.00 Amino-modified silicone surfactant (%) 0.00 0.25 0.00 0.50 Vitamin E (%) 0.125 0.00 0.25 0.125 Cosmosil (ppm) 50 50 50 50 Water (%) 96.88 96.75 96.25 96.38 Number of sticky tips (in 60) 8 0 10 Catheter length, cm (in) 5.07660 5.08076 5.07881 5.07982 [Target length 5.08 cm (2 in)] (1.99866) (2.00030) (1.99953) (1.99993)

If the catheter tip is sticky, the length of the catheter will not be 2.0 inches because it will be stretched as the catheter tip is removed from the mandrel. As can be seen, when the lubricant provided adequate lubricity, the tip did not stick to the mandrel, and the catheter length was very close to the target 5.08 cm (2.0 inches).

If the attachment between the catheter tip and the guide needle is extremely large, the needle cannot be easily removed from the catheter after the assembly has been inserted into the patient's vein. Many thermoplastic materials, such as polyurethane, are extremely sticky and will adhere to metal surfaces under compression. Since the catheter tip is placed with an interference fit over the stainless steel needle, it will stick to the needle unless the needle is lubricated.

Example 2 The following lubricants (lubricants) were used as a tip-forming lubricant during the tip-forming process and for lubricating needles and catheters. A control group was included for comparison.

[0026]

[Table 2] Lubricant needle lubricant for tip molding Catheter lubricant Silicone surfactant (%) 2.375 ± 0.25 2.375 ± 0.25 4.75 ± 0.25 Amino-modified silicone surfactant (%) 0.525 ± 0.025 0.525 ± 0.025 0.525 ± 0.025 Vitamin E (%) 0.2625 ± 0.0125 0.2625 ± 0.0125 0.2625 ± 0.0125 Cosmosil (ppm) 50 50 50 Water (%) 96.8375 ± 0.2875 98.8375 ± 0.2875 94.4625 ± 0.2875 Control DC 12600 cstk Silicone (%)--2.0 Masil 1 MM cstk Silicone ( %)-2.4-PS-513 Amino-modified silicone (%) 0.5--HCFC-141b, Genosolve 2000 (%) 99.5 97.6 98.0

First, a catheter tip forming lubricant for forming a tip on the catheter is used, the needle and the catheter are separately lubricated with the respective lubricants, and finally, the catheter assembly is assembled to a 20 gauge (g).
The catheter product of a) was assembled. 9 of these products
After aged for 2 weeks at 0 ° C., the adhesion at the tip was examined.
Also, for these products, a thickness of 0.343 mm (13.
5 mil) latex transmembrane test. The results are shown in the following table.

[0028]

[Table 3] Control Test tip adhesion catheter drag Tip adhesion catheter drag (lbs) (g) (lbs) (g) Aging deterioration 0 weeks 0.19 3.0 0.12 4.8 1 week, 90 ° C 0.10 4.0 0.11 3.6 2 weeks, 90 ° C 0.16 3.9 0.12 4.7

From the above data, it is clear that the lubricant of the present invention stabilizes tip adhesion and the catheter lubricant properly lubricates the catheter. Furthermore, the properties of the lubricant of the invention are comparable to the control product.

Example 3 Other silicone surfactant combinations were attempted. For example, Silwet L7 similar to Silwet L7001
A polyalkylene oxide-modified polydimethylsiloxane-block copolymer known as 230 was used in combination with an amino-modified silicone-polyether-copolymer known as Silwet Y12593.

[0031]

Ingredients aqueous lubricant silicone 1MM cstk Silwet L7230 (%) 4.50-Silwet Y12593 (%) 0.50-Vitamin E (%) 0.25-Water (%) 94.75-Silicone 1MM cstk (%)-2.4 Freon TF ( %)-97.6

The catheter tube was thermoformed into a catheter adapter using a stainless steel wedge. When placing the catheter assembly over the needle assembly,
Stainless steel wedges and stainless steel needles can cause friction. Therefore, there can be high resistance between these two metal surfaces. This is even more pronounced as the catheter is pushed out of the needle, depending on the angle between the catheter tube and the needle. A study was designed in which the catheter was held fixed at a fixed angle of rotation to ensure that the needle rubbed the wedge. The needle was pulled out and the resistance was measured.
The results are shown below.

[0033]

Table 5 Test Product Resistance (lbs) 20 (ga) catheter not lubricated 0.400 20 (ga) catheter lubricated with silicone 0.160 20 (ga) catheter lubricated with lubricant of the present invention 0.078

These data clearly show that the water-soluble lubricant system of the present invention is effective as a lubricant.

Example 4 To ensure that the solution was homogeneous, a quaternary ammonium salt was used as a solution stabilizer for the tipping lubricant solution. 3% Silwet L7001, 0.5% Sylguard (reactive quaternary compound);
A lubricant containing 25% urea and 96.25% water was used for tipping the catheter. For all products tested, the advanced quality was acceptable. Other quaternary ammonium salts could also be used, for example benzethonium chloride.

Example 5 Various amounts of amino-modified silicone-polyether were used to establish acceptable ranges for use as tipping lubricants.

[0037]

Table 6 1 2 Amino modified silicone surfactant (g) 1.0 10.0 Water (g) 99.0 90.0 tip quality good good

Example 6 The two-component lubricant solution of the present invention was compared with a three-component lubricant solution. The following experiment compares a 4% silicone surfactant solution and a 4% amino-modified silicone surfactant with a ternary lubricant solution. This three-component lubricant solution uses polydimethylsiloxane having an amino terminal group having a viscosity of 2000 centistokes as a lubricant. This product is available from Petrarch Systems under the trade name PS513. 3% PS513 product was mixed with 1% surfactant and 96% water. The surfactant used was Tergitol S, obtained from Union Carbide. The results of tip molding are shown below.

[0039]

Table 7 Parameter PS513 Silicone Amino Modified Emulsion Surfactant Silicone Surfactant Sticky Tip (in 60) 0 0 0 Length of catheter with tip 2.0019 2.0024 1.9889 inches (0.0010) * (0.0014) ** (0.0008 ) * Target length 2.0000 2.0000 2.0000 Notes: () = standard deviation * = 10 samples ** = 8 samples

The results of the lubrication treatment are shown below.

[0041]

[Table 8]Tip adhesion (lbs) Catheter drag (g)  PS513 emulsion 0.21 (0.02) 3.8 (0.4) Silicone surfactant 0.48 (0.05) 5.8 (1.0) Amino-modified silicone surfactant 0.23 (0.06) 3.5 (0.3) Notes: Number of samples = 10 () = standard deviation

These results indicate that the silicone surfactant of the present invention was used as a lubricant and no other surfactant was used.
It clearly shows that the component lubricant solution works similarly to the ternary lubricant solution.

Thus, it can be seen that there is no need to use CFC as a solvent, thus providing a new "environmentally friendly" novel tipping lubricant. Also, the lubricant solution is flame retardant, requires less material than conventional lubricant solutions, and is therefore less expensive.

Continued on the front page (72) Inventor David P. Hopkins, Saltwood City, Utah, USA, Eastwood Drive 3478 (72) Inventor Mohammad A. Khan, Sandy, Utah, South Falcon Hurst Drive 10005

Claims (10)

[Claims] 1. A composition comprising a silicone surfactant and water.
Lubricant solution for tip forming for medical devices. 2. The lubricant solution according to claim 1, wherein the silicone surfactant is a polyalkylene oxide-modified polydimethylsiloxane-block copolymer. 3. The lubricant solution of claim 2, wherein the silicone surfactant comprises about 2% to about 6% of the solution. 4. The lubricant solution of claim 1, wherein the silicone surfactant is a combination of a polyalkylene oxide-modified polydimethylsiloxane-block copolymer and an amino-modified silicone polyether-copolymer. 5. The polyalkylene oxide-modified polydimethylsiloxane-block copolymer and the amino-modified silicone polyether-copolymer together form about 2 to about 2 parts of a solution.
The lubricating solution of claim 4, comprising about 6%. 6. The lubricant solution according to claim 1, wherein the silicone surfactant is an amino-modified silicone polyether-copolymer. 7. The lubricant solution of claim 6, wherein the amino-modified silicone polyether-copolymer comprises from about 2% to about 6% of the solution. 8. The lubricant solution according to claim 1, further comprising vitamin E or a derivative thereof. 9. The method according to claim 8, further comprising a solution stabilizer.
A lubricant solution as described. 10. The method according to claim 1, further comprising an antibacterial agent.
The lubricant solution according to any one of claims 9 to 10.